Cuttings-Transport Modeling–Part 1: Specification of Benchmark Parameters With a Norwegian-Continental-Shelf Perspective

Abstract

Summary In oil and gas drilling, cuttings-transport-related problems are a major contributor to well downtime and costs. As a result, solutions to these problems have been extensively researched over the years, both experimentally and through simulation. Numerous review articles exist, summarizing not only the research history but also the qualitative effect of individual case parameters such as pump-flow rate, pipe rotation, and rate of penetration (ROP) on cuttings transport. However, comparing different studies is challenging because there is no common reference defined in the form of a typical and representative set of case parameters. To develop relevant and accurate cutting-transport models, it is critical that both experiments and models are targeting flow cases relevant for respective drilling operations. Development of a clear understanding of the industrial-parameter space, as well as establishing benchmarks, will help achieve a more-concerted effort in development of models and corresponding laboratory experiments. Other industries have established research benchmarks, such as the “NREL offshore 5-MW baseline wind turbine” (Jonkman et al. 2009) in wind-power research, providing a standardized set of case parameters and profiles, readily available for use to researchers worldwide, and resulting in straightforward benchmarking and validation as well as faster establishment of projects. For application to the modeling of cuttings-transport phenomena, we propose a methodology for deriving a well-defined and standardized set of geometrical, operational, and environmental case parameters describing various operating points of drilling operations and procedures as well as simplified problems. The methodology is exemplified with an 8.5-in.-section drilling-ahead use case with aggregated wellbore data from the Norwegian Petroleum Directorate (NPD). The relevance and application of the derived parameters are briefly discussed in light of modeling, both experimentally and through simulations. Applying this methodology before any cuttings-transport study may enable a better definition of industry-relevant case parameters. In Part 2, we will apply and discuss the derived parameter sets in the context of nondimensional numbers for assessment of scalability.